Work-holding attachment for drills.



No. 700,964. I Patented Mav 27, I902.

G. E. METCALF. WORK HOLDING ATTACHMENT FOR DBILLS.

(Application filed Dec. 26, 1901,)

(No Model.)

-- I71 dew-r606.-

Geo; eEZWZ a/ 29 9 C I rr j T I iii 01 7195 TOThflei-Bses;

PATENT @FrrcE GEORGE E. METOALF, OF WORCESTER, MASSACHUSETTS.

WORK-HOLDING ATTACHMENT FOR DRILLS.

SPECIFICATION forming part of Letters Patent No. 700,964, dated May 27, 1902.

Application filed December 26,1901. Serial ITO-87,318. (No model.)

To (tZZ whom it may concern:

Be it known that I, GEORGE E. METCALF, a citizen of the United States, residing at WVorcester, in the county of WVorcester and State of Massachusetts, have invented a new and useful Work-Holding Attachment for Drills, of which the following is a specification.

This invention relates to an attachment for drilling-machines, which has been designed with aview of providing a simple and efficient construction for holding and presenting small parts in place to be drilled.

To these ends this invention consists of the parts and combinations of parts, as hereinafter described, and more particularly pointed out in the claims at the end of this specifier); tion.

In the accompanying drawings, Figure 1 is a perspective View of sufficient parts of an attachment for drilling-machines constructed according to my invention to illustrate the operation thereof. Fig. 2 is a side view of the same, and Fig. 3 is a detail perspective View showing the construction for moving the end of the positioning-spring out of the.

path of the rotary holder when the same is to be advanced to bringa fresh piece of work into position to be drilled.

In the construction of many devices in which small working parts are employed-as, for example, in pistol-shops, type-writerfactories, and in similar industries-one of the largest items of cost is the drilling of pivot or rivet holes in the smaller parts or pieces. For doing this class of work it has heretofore been customary to employ jigs of various kinds, the best results being ordinarily secured by clamping-jigs in which one piece of work at a time is first clamped in place and then brought to position to present the workin place to be acted upon by the drill. Drilling small parts in this manner necessarily requires considerable time for each piece operated upon and also requires skilled labor for producing uniform results.

The especial object of my present invention is to provide an attachment for drillingmachines which will present successive pieces in position to be drilled with absolute accuracy and uniformity and which will not waste the time heretofore required for clamping and unclamping the work in the ordinary forms of'jigs.

To these ends an attachment for drillingmachines constructed according to my inven- 'tion consists, essentially,'of a rotary holder The work-receiving sockets in the rotary holder are preferably open, so that the work will drop down out of the same when carried off from the surface of the base-piece or table.

The stopping devices in an attachment for drills constructed according to my invention preferably comprise a holding-stop arranged to permit the rotary holder to ratchet past the same and a positioning-spring tending to turn the rotary holder back against the holding-stop. Cooperating with the positioningspring is a cam or other suitable connections for movingthe positioning-springout of the path of the rotary holder 'when the rotary holder is advanced to bring a fresh piece of work into place.

In practice the end of the positioning-spring is preferably arranged to engage one side of the piece of work which is about to be drilled, so that the positioning-spring not only will perform the work of tending to turn the rotary holder back against the holding-stop, but will also force the piece of work about to be drilled against the farther side of the workreceiving socket, so that each piece of work as it is drilled will be set and positioned with the greatest possible accuracy.

Referring to the accompanying drawings for a detail description of an attachment for drilling-machines constructed according to my invention, the attachment comprises a base-piece or table 10, which may be supported upon suitable legs 11, as shown in Fig. 2, and is adapted to be clamped or otherwise socured in place on a drill-table or other support in position to cooperate with a drill D. J ournaled upon a stud 12 near the front edge ICO of the table or support is a rotary holder. As herein illustrated, the rotary holder comprises a center piece or hub 13, having four extending arms 14. Each of the extending arms 14: is inclined or beveled at its end to codperate with a holding-stop 15 and is provided with a work-holding socket 16. The holding-stop 15 consists of a piece of springsteel fastened in place by a screw 17, so that the successive arms 14 of the rotary holder may ratchet past the same, the outward motion of the holding-stop 15 being limited by a pin 18. As the rotary holder is turned its arms 14: will pass successively under a bridgepiece l9,which bridge-piece 19 is held in place by screws 20 and is provided with a bushing 21 for receiving the end of the drill D.

As illustrated in Fig. 2, a chip-guard may be secured upon the bridge-piece 19 to prevent the chips from falling on the table in the path of the rotary holder. Cooperating with each arm 14 of the rotary holder as the same is brought in place under the bridgepiece 19 is a positioning-spring 22. The positioning-spring 22 is secured at its outer end by a screw 23 in a socket-piece 24. As shown most clearly in Fig. 2, the socket-piece 24 may be turned to vary the tension of the holding-spring 22 and may be clamped in its adjusted position by a nut 25.

In practice the end of the positioning-spring may engage the forward edge of each successive arm 14 of the rotary holder, although in practice, as most clearly illustrated in Fig. 3, I preferably provide a groove or socket 26 in each of the arms 14: to permit the end of the holding-spring to act directly upon the forward edge of each piece of workW as the same is brought into position to be drilled, and I consider this a feature of advantage, as by means of this construction the positioning-spring 22 not only tends to turn the rotary holder back against the holding-stop 15, but also serves to crowd each piece of work against the farther side of its socket, so that successive pieces of work will all be gaged from the farther side of their sockets and will be drilled with the most absolute accuracy. When the rotary holder is to be turned to bring a succeeding piece of work into position to be drilled, it is necessary to provide some means for moving the end of the positioning-spring out of the path of the rotary holder. For this purpose I preferably provide an inclined piece or cam for lifting the positioning-spring.

As shown in Fig. 1, a cam-plate 27 is secured to the table or base-plate 10 by a bolt 28, and, as shown most clearly in Fig. 3, the plate 27 is provided at its ends with an inclined section or cam 29, which lifts the positioning-spring clear of the rotary holder when the same is turned and permits the positioning-spring to fly back into place to cooperate with the succeeding arm of the rotary holder.

I am aware that numerous changes may be made in the construction of my attachment for drilling-machines by those who are skilled in the art without departing from the scope of my invention as expressed in the claims. I do not wish, therefore, to be limited to the construc-' tion I have herein shown and described; but

What I do claim, and desire to secure by Letters Patent of the United States, is

1. In a device of the class described, the combination of a table or plate and a rotary work-holder having a work-receiving socket, said parts being-arranged so that by turning the rotary holder to bring its socket over the plate or table, a piece to be drilled may be first placed in said socket and then moved along over the table or plate to be presented in proper position to be acted upon by a drill, after. which the continued rotation of the holder will carry the same 0% from the plate or table so that it may drop down through the socket in the rotary holder.

2. In a device of the class described, the combination of a rotary holder, and stopping devices therefor, comprising a holding-stop arranged to permit the holder to ratchet past the same, and a positioning-spring tending to turn the holder back against the holding-stop.

3. In a device of the class described, the combination of a rotary holder, and stopping devices therefor, comprising a holding-stop arranged to permit the holder to ratchet past the same, a positioningspring tending to move the rotary holder back against the holding-stop, and means for moving the positioning-spring out of the path of the rotary holder. 4. In a device of the class described, the combination of a rotary holder comprising a plurality of arms, a holding-stop permitting the arms of the rotary holder to ratchet past the same, a positioning-spring tending to move the rotary holder back against the holding-stop, and a cam for lifting the end of the positioning-spring out of the path of the r0- tary holder, to permit the same to fly back into position to cooperate with a succeeding arm of the rotary holder.

5. In a device of the class described, the combination of a rotary holder having extending arms, each of which is provided with a work-receiving socket, and stopping devices therefor, comprising a holding-stop arranged to permit the rotary holder to ratchet past the same, and a positioning-spring arranged to engage the forward side of each piece of work as the same is brought into position, whereby said positioning-spring tends to turn the rotary holder back against the holdingstop, and also serves to gage the piece of work about to be acted upon.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

GEORGE E. METCALF. l/Vitnesses:

LOUIS W. SOUTHGATE, PHILIP W. SOUTHGATE. 

